code: def wpe_manager(
      wav_scp,
      processing_num=1,
      data_root="MISP_121h",
      output_root="MISP_121h_WPE_",
  ):
      if processing_num > 1:
          pool = Pool(processes=processing_num)
          for i in range(processing_num):
              pool.apply_async(
                  wpe_worker,
                  kwds={
                      "wav_scp": wav_scp,
                      "processing_id": i,
                      "processing_num": processing_num,
                      "data_root": data_root,
                      "output_root": output_root,
                  },
              )
          pool.close()
          pool.join()
      else:
          wpe_worker(
              wav_scp, data_root=data_root, output_root=output_root
          )
      return None
  
file_path: espnet/egs2/misp2021/asr1/local/run_wpe.py
imports: import argparse
  import codecs
  import os
  from multiprocessing import Pool
  import numpy
  import scipy.io.wavfile
  from nara_wpe.utils import istft, stft
  from nara_wpe.wpe import wpe_v8
label_desc: Use image node_id 2 for calling a global function with example usage: wpe_manager(wav_scp, processing_num, data_root, output_root) and returns: None